source4/lib/ldb/common/ldb_match.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Andrew Tridgell  2004-2005
   5    Copyright (C) Simo Sorce            2005
   6
   7      ** NOTE! The following LGPL license applies to the ldb
   8      ** library. This does NOT imply that all of Samba is released
   9      ** under the LGPL
  10
  11    This library is free software; you can redistribute it and/or
  12    modify it under the terms of the GNU Lesser General Public
  13    License as published by the Free Software Foundation; either
  14    version 3 of the License, or (at your option) any later version.
  15
  16    This library is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19    Lesser General Public License for more details.
  20
  21    You should have received a copy of the GNU Lesser General Public
  22    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 /*
  26  *  Name: ldb
  27  *
  28  *  Component: ldb expression matching
  29  *
  30  *  Description: ldb expression matching
  31  *
  32  *  Author: Andrew Tridgell
  33  */
  34
  35 #include "ldb_private.h"
  36
  37 /*
  38   check if the scope matches in a search result
  39 */
  40 static int ldb_match_scope(struct ldb_context *ldb,
  41                            struct ldb_dn *base,
  42                            struct ldb_dn *dn,
  43                            enum ldb_scope scope)
  44 {
  45         int ret = 0;
  46
  47         if (base == NULL || dn == NULL) {
  48                 return 1;
  49         }
  50
  51         switch (scope) {
  52         case LDB_SCOPE_BASE:
  53                 if (ldb_dn_compare(base, dn) == 0) {
  54                         ret = 1;
  55                 }
  56                 break;
  57
  58         case LDB_SCOPE_ONELEVEL:
  59                 if (ldb_dn_get_comp_num(dn) == (ldb_dn_get_comp_num(base) + 1)) {
  60                         if (ldb_dn_compare_base(base, dn) == 0) {
  61                                 ret = 1;
  62                         }
  63                 }
  64                 break;
  65
  66         case LDB_SCOPE_SUBTREE:
  67         default:
  68                 if (ldb_dn_compare_base(base, dn) == 0) {
  69                         ret = 1;
  70                 }
  71                 break;
  72         }
  73
  74         return ret;
  75 }
  76
  77
  78 /*
  79   match if node is present
  80 */
  81 static int ldb_match_present(struct ldb_context *ldb,
  82                              const struct ldb_message *msg,
  83                              const struct ldb_parse_tree *tree,
  84                              enum ldb_scope scope)
  85 {
  86         if (ldb_attr_dn(tree->u.present.attr) == 0) {
  87                 return 1;
  88         }
  89
  90         if (ldb_msg_find_element(msg, tree->u.present.attr)) {
  91                 return 1;
  92         }
  93
  94         return 0;
  95 }
  96
  97 static int ldb_match_comparison(struct ldb_context *ldb,
  98                                 const struct ldb_message *msg,
  99                                 const struct ldb_parse_tree *tree,
 100                                 enum ldb_scope scope,
 101                                 enum ldb_parse_op comp_op)
 102 {
 103         unsigned int i;
 104         struct ldb_message_element *el;
 105         const struct ldb_schema_attribute *a;
 106         int ret;
 107
 108         /* FIXME: APPROX comparison not handled yet */
 109         if (comp_op == LDB_OP_APPROX) return 0;
 110
 111         el = ldb_msg_find_element(msg, tree->u.comparison.attr);
 112         if (el == NULL) {
 113                 return 0;
 114         }
 115
 116         a = ldb_schema_attribute_by_name(ldb, el->name);
 117
 118         for (i = 0; i < el->num_values; i++) {
 119                 ret = a->syntax->comparison_fn(ldb, ldb, &el->values[i], &tree->u.comparison.value);
 120
 121                 if (ret == 0) {
 122                         return 1;
 123                 }
 124                 if (ret > 0 && comp_op == LDB_OP_GREATER) {
 125                         return 1;
 126                 }
 127                 if (ret < 0 && comp_op == LDB_OP_LESS) {
 128                         return 1;
 129                 }
 130         }
 131
 132         return 0;
 133 }
 134
 135 /*
 136   match a simple leaf node
 137 */
 138 static int ldb_match_equality(struct ldb_context *ldb,
 139                               const struct ldb_message *msg,
 140                               const struct ldb_parse_tree *tree,
 141                               enum ldb_scope scope)
 142 {
 143         unsigned int i;
 144         struct ldb_message_element *el;
 145         const struct ldb_schema_attribute *a;
 146         struct ldb_dn *valuedn;
 147         int ret;
 148
 149         if (ldb_attr_dn(tree->u.equality.attr) == 0) {
 150                 valuedn = ldb_dn_from_ldb_val(ldb, ldb, &tree->u.equality.value);
 151                 if (valuedn == NULL) {
 152                         return 0;
 153                 }
 154
 155                 ret = ldb_dn_compare(msg->dn, valuedn);
 156
 157                 talloc_free(valuedn);
 158
 159                 if (ret == 0) return 1;
 160                 return 0;
 161         }
 162
 163         /* TODO: handle the "*" case derived from an extended search
 164            operation without the attibute type defined */
 165         el = ldb_msg_find_element(msg, tree->u.equality.attr);
 166         if (el == NULL) {
 167                 return 0;
 168         }
 169
 170         a = ldb_schema_attribute_by_name(ldb, el->name);
 171
 172         for (i=0;i<el->num_values;i++) {
 173                 if (a->syntax->comparison_fn(ldb, ldb, &tree->u.equality.value,
 174                                              &el->values[i]) == 0) {
 175                         return 1;
 176                 }
 177         }
 178
 179         return 0;
 180 }
 181
 182 static int ldb_wildcard_compare(struct ldb_context *ldb,
 183                                 const struct ldb_parse_tree *tree,
 184                                 const struct ldb_val value)
 185 {
 186         const struct ldb_schema_attribute *a;
 187         struct ldb_val val;
 188         struct ldb_val cnk;
 189         struct ldb_val *chunk;
 190         char *p, *g;
 191         uint8_t *save_p = NULL;
 192         unsigned int c = 0;
 193
 194         a = ldb_schema_attribute_by_name(ldb, tree->u.substring.attr);
 195
 196         if(a->syntax->canonicalise_fn(ldb, ldb, &value, &val) != 0)
 197                 return -1;
 198
 199         save_p = val.data;
 200         cnk.data = NULL;
 201
 202         if ( ! tree->u.substring.start_with_wildcard ) {
 203
 204                 chunk = tree->u.substring.chunks[c];
 205                 if(a->syntax->canonicalise_fn(ldb, ldb, chunk, &cnk) != 0) goto failed;
 206
 207                 /* This deals with wildcard prefix searches on binary attributes (eg objectGUID) */
 208                 if (cnk.length > val.length) {
 209                         goto failed;
 210                 }
 211                 if (memcmp((char *)val.data, (char *)cnk.data, cnk.length) != 0) goto failed;
 212                 val.length -= cnk.length;
 213                 val.data += cnk.length;
 214                 c++;
 215                 talloc_free(cnk.data);
 216                 cnk.data = NULL;
 217         }
 218
 219         while (tree->u.substring.chunks[c]) {
 220
 221                 chunk = tree->u.substring.chunks[c];
 222                 if(a->syntax->canonicalise_fn(ldb, ldb, chunk, &cnk) != 0) goto failed;
 223
 224                 /* FIXME: case of embedded nulls */
 225                 p = strstr((char *)val.data, (char *)cnk.data);
 226                 if (p == NULL) goto failed;
 227                 if ( (! tree->u.substring.chunks[c + 1]) && (! tree->u.substring.end_with_wildcard) ) {
 228                         do { /* greedy */
 229                                 g = strstr((char *)p + cnk.length, (char *)cnk.data);
 230                                 if (g) p = g;
 231                         } while(g);
 232                 }
 233                 val.length = val.length - (p - (char *)(val.data)) - cnk.length;
 234                 val.data = (uint8_t *)(p + cnk.length);
 235                 c++;
 236                 talloc_free(cnk.data);
 237                 cnk.data = NULL;
 238         }
 239
 240         if ( (! tree->u.substring.end_with_wildcard) && (*(val.data) != 0) ) goto failed; /* last chunk have not reached end of string */
 241         talloc_free(save_p);
 242         return 1;
 243
 244 failed:
 245         talloc_free(save_p);
 246         talloc_free(cnk.data);
 247         return 0;
 248 }
 249
 250 /*
 251   match a simple leaf node
 252 */
 253 static int ldb_match_substring(struct ldb_context *ldb,
 254                                const struct ldb_message *msg,
 255                                const struct ldb_parse_tree *tree,
 256                                enum ldb_scope scope)
 257 {
 258         unsigned int i;
 259         struct ldb_message_element *el;
 260
 261         el = ldb_msg_find_element(msg, tree->u.substring.attr);
 262         if (el == NULL) {
 263                 return 0;
 264         }
 265
 266         for (i = 0; i < el->num_values; i++) {
 267                 if (ldb_wildcard_compare(ldb, tree, el->values[i]) == 1) {
 268                         return 1;
 269                 }
 270         }
 271
 272         return 0;
 273 }
 274
 275
 276 /*
 277   bitwise-and comparator
 278 */
 279 static int ldb_comparator_and(const struct ldb_val *v1, const struct ldb_val *v2)
 280 {
 281         uint64_t i1, i2;
 282         i1 = strtoull((char *)v1->data, NULL, 0);
 283         i2 = strtoull((char *)v2->data, NULL, 0);
 284         return ((i1 & i2) == i2);
 285 }
 286
 287 /*
 288   bitwise-or comparator
 289 */
 290 static int ldb_comparator_or(const struct ldb_val *v1, const struct ldb_val *v2)
 291 {
 292         uint64_t i1, i2;
 293         i1 = strtoull((char *)v1->data, NULL, 0);
 294         i2 = strtoull((char *)v2->data, NULL, 0);
 295         return ((i1 & i2) != 0);
 296 }
 297
 298
 299 /*
 300   extended match, handles things like bitops
 301 */
 302 static int ldb_match_extended(struct ldb_context *ldb,
 303                               const struct ldb_message *msg,
 304                               const struct ldb_parse_tree *tree,
 305                               enum ldb_scope scope)
 306 {
 307         unsigned int i;
 308         const struct {
 309                 const char *oid;
 310                 int (*comparator)(const struct ldb_val *, const struct ldb_val *);
 311         } rules[] = {
 312                 { LDB_OID_COMPARATOR_AND, ldb_comparator_and},
 313                 { LDB_OID_COMPARATOR_OR, ldb_comparator_or}
 314         };
 315         int (*comp)(const struct ldb_val *, const struct ldb_val *) = NULL;
 316         struct ldb_message_element *el;
 317
 318         if (tree->u.extended.dnAttributes) {
 319                 /* FIXME: We really need to find out what this ":dn" part in
 320                  * an extended match means and how to handle it. For now print
 321                  * only a warning to have s3 winbind and other tools working
 322                  * against us. - Matthias */
 323                 ldb_debug(ldb, LDB_DEBUG_WARNING, "ldb: dnAttributes extended match not supported yet");
 324         }
 325         if (tree->u.extended.rule_id == NULL) {
 326                 ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb: no-rule extended matches not supported yet");
 327                 return -1;
 328         }
 329         if (tree->u.extended.attr == NULL) {
 330                 ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb: no-attribute extended matches not supported yet");
 331                 return -1;
 332         }
 333
 334         for (i=0;i<ARRAY_SIZE(rules);i++) {
 335                 if (strcmp(rules[i].oid, tree->u.extended.rule_id) == 0) {
 336                         comp = rules[i].comparator;
 337                         break;
 338                 }
 339         }
 340         if (comp == NULL) {
 341                 ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb: unknown extended rule_id %s",
 342                           tree->u.extended.rule_id);
 343                 return -1;
 344         }
 345
 346         /* find the message element */
 347         el = ldb_msg_find_element(msg, tree->u.extended.attr);
 348         if (el == NULL) {
 349                 return 0;
 350         }
 351
 352         for (i=0;i<el->num_values;i++) {
 353                 int ret = comp(&el->values[i], &tree->u.extended.value);
 354                 if (ret == -1 || ret == 1) return ret;
 355         }
 356
 357         return 0;
 358 }
 359
 360 /*
 361   return 0 if the given parse tree matches the given message. Assumes
 362   the message is in sorted order
 363
 364   return 1 if it matches, and 0 if it doesn't match
 365
 366   this is a recursive function, and does short-circuit evaluation
 367  */
 368 static int ldb_match_message(struct ldb_context *ldb,
 369                              const struct ldb_message *msg,
 370                              const struct ldb_parse_tree *tree,
 371                              enum ldb_scope scope)
 372 {
 373         unsigned int i;
 374         int v;
 375
 376         switch (tree->operation) {
 377         case LDB_OP_AND:
 378                 for (i=0;i<tree->u.list.num_elements;i++) {
 379                         v = ldb_match_message(ldb, msg, tree->u.list.elements[i], scope);
 380                         if (!v) return 0;
 381                 }
 382                 return 1;
 383
 384         case LDB_OP_OR:
 385                 for (i=0;i<tree->u.list.num_elements;i++) {
 386                         v = ldb_match_message(ldb, msg, tree->u.list.elements[i], scope);
 387                         if (v) return 1;
 388                 }
 389                 return 0;
 390
 391         case LDB_OP_NOT:
 392                 return ! ldb_match_message(ldb, msg, tree->u.isnot.child, scope);
 393
 394         case LDB_OP_EQUALITY:
 395                 return ldb_match_equality(ldb, msg, tree, scope);
 396
 397         case LDB_OP_SUBSTRING:
 398                 return ldb_match_substring(ldb, msg, tree, scope);
 399
 400         case LDB_OP_GREATER:
 401                 return ldb_match_comparison(ldb, msg, tree, scope, LDB_OP_GREATER);
 402
 403         case LDB_OP_LESS:
 404                 return ldb_match_comparison(ldb, msg, tree, scope, LDB_OP_LESS);
 405
 406         case LDB_OP_PRESENT:
 407                 return ldb_match_present(ldb, msg, tree, scope);
 408
 409         case LDB_OP_APPROX:
 410                 return ldb_match_comparison(ldb, msg, tree, scope, LDB_OP_APPROX);
 411
 412         case LDB_OP_EXTENDED:
 413                 return ldb_match_extended(ldb, msg, tree, scope);
 414
 415         }
 416
 417         return 0;
 418 }
 419
 420 int ldb_match_msg(struct ldb_context *ldb,
 421                   const struct ldb_message *msg,
 422                   const struct ldb_parse_tree *tree,
 423                   struct ldb_dn *base,
 424                   enum ldb_scope scope)
 425 {
 426         if ( ! ldb_match_scope(ldb, base, msg->dn, scope) ) {
 427                 return 0;
 428         }
 429
 430         return ldb_match_message(ldb, msg, tree, scope);
 431 }
 432
 433 int ldb_match_msg_objectclass(const struct ldb_message *msg,
 434                               const char *objectclass)
 435 {
 436         int i;
 437         struct ldb_message_element *el = ldb_msg_find_element(msg, "objectClass");
 438         if (!el) {
 439                 return 0;
 440         }
 441         for (i=0; i < el->num_values; i++) {
 442                 if (ldb_attr_cmp((const char *)el->values[i].data, objectclass) == 0) {
 443                         return 1;
 444                 }
 445         }
 446         return 0;
 447 }
 448
 449
 450